I need to find memory leaks in Flutter. How to find them? and how to create memory leaks for the test?
Detect. Add LeakNavigatorObserver to navigatorObservers in MaterialApp , it will automatically detect whether there is a memory leak in the page's Widget and its corresponding Element object. If page's Widget is a StatefulWidget , it will also be automatically checked Its corresponding State .
The primary tools for detecting memory leaks are the C/C++ debugger and the C Run-time Library (CRT) debug heap functions. The #define statement maps a base version of the CRT heap functions to the corresponding debug version. If you leave out the #define statement, the memory leak dump will be less detailed.
In-depth analysis of Flutter rendering, concluded that the root cause of Image and Picture leakage is the leakage of BuildContext.
User and Flutter EventExpand the events at the bottom of the hover card to display all events for that timestamp. Displayed below the events pane is the memory chart and the Android memory chart.
There is a memory leak detection tool LeakCanary on the Android platform that can easily detect if the current page is leaking in a debug environment. This article will take you through the implementation of a flutter -ready LeakCanary and tell you how I used it to detect two leaks on the 1.9.1 framework.
First look at why the leak path is so long, by observing the returned link found that the majority of nodes are flutter UI component nodes (for example: widget, element, state, renderObject).
Add LeakNavigatorObserver to navigatorObservers in MaterialApp, it will automatically detect whether there is a memory leak in the page's Widget and its corresponding Element object. If page's Widget is a StatefulWidget, it will also be automatically checked Its corresponding State.
It is easy to know whether a variable is correctly reclaimed by memory. By using the reference as the key of the weak reference, when the GC is executed, if the reference can be recycled, it will be deleted from the weak reference.
Am implemented Memory leack testing in android studio ide.
Step - 1 : Connect your device with android studio and run your application on your device.
Step - 2 : Go to View -> Tool Windows -> Flutter Performance
Step - 3 : Bottom of the window "Open Dev Tools" option will be there, click on it. It will be navigate into new window of your browser. See below image for more details :
Step - 4 : To follow below steps as per screen shot , you can able to see object size and details.Which are caused memory leakages. First Select "Memory" from available menus than you can able to see below ui.
1. Click on settings icon
2. Select "Dart" and "Flutter" from checkbox.
3. Click on "Apply" button.
Step - 5 : This is final step, now you can able to see memory leaking info.
1. Click on "Snapshot" it will be collect and display object list in bottom of the window.
2. Click on search icon and Here you can see those classes which objects are not destroyed. Suppose am selected "ApiRepository.dart" class and instance will be available in memory ,so that details are visible in window. If multiple objects created than you can see here the total no. of instance and total size.
Step - 6 : You can able to call Garbage Collector manually by using "GC" . You can anytime Reset and get latest snapshot using "Reset" and "Snapshot" buttons.
For more information about Memory allocation related details read below articles :
https://medium.com/flutter/flutter-dont-fear-the-garbage-collector-d69b3ff1ca30 https://flutter.dev/docs/development/tools/devtools/memory
UPDATED: devtools/memory
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With